Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D265/00—Heterocyclic compounds containing six-membered rings having one nitrogen atom and one oxygen atom as the only ring hetero atoms
  • C07D265/04—1,3-Oxazines; Hydrogenated 1,3-oxazines
  • C07D265/12—1,3-Oxazines; Hydrogenated 1,3-oxazines condensed with carbocyclic rings or ring systems
  • C07D265/14—1,3-Oxazines; Hydrogenated 1,3-oxazines condensed with carbocyclic rings or ring systems condensed with one six-membered ring
  • C07D265/20—1,3-Oxazines; Hydrogenated 1,3-oxazines condensed with carbocyclic rings or ring systems condensed with one six-membered ring with hetero atoms directly attached in position 4
  • C07D265/22—Oxygen atoms

Definitions

• 5-fluoro-2-phenyl-4H-3,1-benzoxazin-4-ones are herbicidally active and are notable for high activity and a broad spectrum of activity (DE-OS 29 14 915, DE-OS 30 00 309, DE- OS 30 37 970).
• Typical compounds of this type are described, for example, by the general formula (1) in which R is hydrogen, halogen, C 1 - to C 3 -alkyl, m- or p-position trifluoromethyl, trifluoromethoxy, chlorodifluoromethoxy, difluoromethoxy, tetrafluoroethoxy, trifluoromethylmercapto or chlorodifluoromethylmercapto.
• the compounds (I) are usually prepared by reacting 6-fluoroanthranilic acid with appropriately substituted or unsubstituted benzoyl halide and cyclization (cf. above).
• potassium fluoride is nucleophilic on the one hand sulfite esters (J.Org.Chem. 31, 842 (1966)) and acyl esters (J.Chem.Soc. 1962, 1056; J.Chem.Soc. Perkin Trans. I, 1978, 269) with elimination of the acyl group, but that it also slightly decarboxylates aromatic carboxylic acids, for example anthranilic acid (CA 42, 4924 g).
• 5-fluoro-2-phenyl-4H-3,1-benzoxazin-4-one of the formula (I) explained in more detail above can be obtained from corresponding chlorine, bromine or iodine, nitro, mesyl or tosyl substituted 2-phenyl-4H-3,1-benzoxazin-4-ones (II) if they are reacted with alkali metal fluoride with the exclusion of water .
• the starting compounds can be reacted with stoichiometric or excess amounts of (alkyl) ammonium fluoride or alkali metal fluoride, preferably with potassium fluoride, advantageously 1 to 5 mol, preferably 1 to 1.5 mol, in particular 1 to 1.15 mol, per mol of benzoxazinone.
• the reaction in the presence of a solvent proceeds in good yield at about 160 to 250 ° C., preferably at 180 to 230 ° C., at atmospheric or, if necessary, increased pressure, batchwise or continuously. Above this temperature range, the yields deteriorate Dimethylformamide, dimethyl sulfoxide, a polyethylene glycol dialkyl ether, acetonitrile, hexamethylphosphoric acid triamide, an open-chain or cyclic sulfone, such as sulfolane, are suitable, but if you want to work without a solvent, a temperature above 250 ° C., for example 300 to 500 ° C., must be used which, in this case, is borne contrary to the expectations of the starting and target substances.
• potassium fluoride When working in a solvent, the addition of a solubilizer is highly recommended - especially when using potassium fluoride. Suitable are e.g. Crown ethers, polyethylene glycols or their derivatives. Cesium fluoride is relatively soluble. In contrast, potassium or ammonium fluoride is usually preferred and a sulfone, e.g. Sulfolan. If cesium fluoride is used, an intermediary can be dispensed with and - for economic reasons - can be stretched or regenerated with another fluoride.
• a further improvement of the process is achieved by carrying out the reaction in the presence of a metal iodide or iodine, which inhibit decomposition reactions of the heterocycle associated with the halogen exchange.
• the amount of iodide or iodine is e.g. 1 to 10, in particular 0.1 to 5 mol.%, Based on benzoxazinone.
• Anhydrous reaction conditions are a prerequisite for the process according to the invention.
• Pretreatment if limited to this, can be carried out at a temperature below 120 ° C.
• N-disubstituted carbonamides with 3 to 10 carbon atoms are suitable, such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-di-n-propylacetamide, N-methyl N-ethyl-formamide or N, N-di-isopropylacetamide.
• the catalyst is advantageously used in an amount of 0.2 to 2 percent by weight based on the acid halide.
• the alkali metal fluoride can also be pretreated with one of the abovementioned acid halides in the same way, if appropriate in an inert solvent which boils up to 120 °.
• the alkali metal fluoride is expediently suspended in the excess solvent and the acid halide is then added, advantageously in an amount of up to 100% by weight, preferably from 2 to 30% by weight, based on the alkali metal fluoride.
• the mixture is then stirred with heating, for example up to 120 ° C., expediently between 50 to 110 ° C., in particular at 70 to 100 ° C., and then concentrated at 10 to 30 mbar. Treatment usually lasts no more than 2 hours.
• the potassium fluoride treated in this way is then added to a mixture of untreated or pretreated starting material II with the aliphatic sulfone.
• the mixture of the starting material II with the aliphatic sulfone can - as described - with an acid Pretreat chloride and then add dry, untreated alkali fluoride, metal iodide and / or iodine after the evolution of gas has ended.
• the starting material (benzoxazinone; II), the sulfone, the metal iodide and the acid halide can be mixed with one another in any order.
• the starting material II is first mixed at 30 to 40 ° C. with the metal iodide and the sulfone III and, if appropriate, with a catalyst, the acid halide is then added with stirring and the mixture is expediently heated until gas evolution is no longer observed.
• Excess acid halide e.g. by blowing nitrogen or the like or remove by applying reduced pressure.
• metal iodide and in particular elemental iodine - because of its volatility - only after the acid halide treatment of the starting material II in the sulfone.
• the carefully dried starting materials II, potassium fluoride, sulfolane, metal iodide and / or iodine are mixed with the acid halide and the reaction is then carried out.
• iodide or iodine can only be added later in the course of the reaction, but at the latest after half of the reaction, i.e. Response time, admit.
• the remaining amount of the acid halide should expediently not exceed 1 to 5 mol percent, based on the alkali metal fluoride, in the actual reaction.
• the residual amount of acid halide which is still present after the pretreatment of the mixture of starting material II and aliphatic sulfone after blowing in an inert gas or reducing the pressure to 10 to 30 mbar is sufficient to treat the alkali metal fluoride which is added in order to start the actual reaction.
• the catalysts are expediently used in an effective amount of up to 0.5, in particular 0.1 to 0.3 mol percent per mol of starting material II.
• the fluorine salt is still water-containing, it is first dried under the reaction conditions, if appropriate under reduced pressure, and then the starting material II is metered in.
• reaction is stirred further after initial mixing Mixture is not required to complete the reaction.
• the reaction can therefore also be carried out in the manner of a baking process or in a tubular reactor.
• the reaction temperature can be adapted to certain equipment conditions and heating options, but should advantageously be at least 290 ° C to 300 ° C. Correspondingly long reaction times must be selected in this lower temperature range, for example 18 to 24 hours at 300 . C. In a medium temperature range, for example 380 ° C, the reaction time is about 25 to 35 minutes and is shortened accordingly at even higher temperatures.
• the end products are distilled directly from the reaction mixture to the extent that they are formed.
• reaction temperature 320 to 410 ° C. is selected; If the starting material II is added in gaseous form, an even higher reaction temperature can be selected, the reaction being carried out under atmospheric pressure or under reduced pressure.
• the corresponding 5-chloro compound can be prepared in a corresponding manner: 5-fluoro-2- (3'-trifluoromethylphenyl) -4H-3, l-benzoxazin-4-one, 5-fluoro-2- (4th '-trifluoromethyl-phenyl) -4H-3,1-benzoxazin-4-one, 5-fluoro-2- (3'-fluorophenyl) -4H-3,1-benzoxazin-4-one, 5-fluoro- 2 - (3'-chlorophenyl) -4H-3,1-benzoxazin-4-one, 5-fluoro-2- (4'-trifluoromethoxy-phenyl) -4H-3,1-benzoxazin-4-one, 5-fluoro-2- (3'-trifluoromethoxyphenyl) - -4H-3,1-benzoxazin-4-one, 5-fluoro-2- (3'-trifluoromethoxyphenyl) - -4H-3
• the distilled sulfolane still contains 0.3 kg of 5-fluoro-2-phenyl-4H-3.1-benzoxazin-4-one.
• the total yield of fluorine compound is thus 13 kg (over 65% of the calculated amount). Further cleaning is not necessary for plant protection purposes, since the corresponding chlorine compound, which is less effective, does not interfere.
• a mixture of 20 g of 5-chloro-2-phenyl-4H-3, l-benzoxazin-4-one, 68 g of sulfolane, 0.8 g of sodium iodide and 5 g of thionyl chloride is stirred at 95 to 100 ° C for 40 minutes and then brought to a reduced pressure of 26 mbar for 20 minutes at 98 ° C. 6.76 g of thionyl chloride-treated potassium fluoride (Example 3a) are then added under a nitrogen blanket and the mixture is stirred at 220 ° C. for 5 hours.
• the reaction mixture is diluted with methylene chloride and separated from the predominantly inorganic precipitate (10.2 g).
• the filtrate is freed from methylene chloride on a rotary evaporator at 50 ° C./12 mbar and then sulfolane (63.7 g) is removed in a distillation apparatus at 81 to 86 ° C./0.2 mbar.
• the residue is then distilled over a heated bridge at a bath temperature of up to 220 ° C / 0.2 mbar, 19 g of almost colorless product passing over with a remainder of sulfolane.
• a mixture of 20 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one, 68 g of sulfolane and 5 g of thionyl chloride is stirred at 100 ° C. for 30 minutes and then at 110 ° C. for 30 minutes. 19 mbar evacuated. 6.35 g of thermally dried potassium fluoride and 0.066 g of thionyl chloride are added under a nitrogen blanket and the mixture is stirred at 240 ° C. for 15 minutes. After adding 0.25 g of iodine, the mixture is stirred at 240 ° C. for a further 3.5 hours.
• a mixture of 20 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one, 68 g of sulfolane and 5 g of thionyl chloride is stirred at 100 ° C. for 30 minutes and then up to 102 ° C./22 mbar during Under a nitrogen blanket, 6.35 g of thionyl chloride-treated potassium fluoride and 0.25 g of iodine are added and the mixture is then stirred at 260 ° C. for 2 hours.
• a mixture of 200 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one, 649 g of sulfolane and 60 g of thionyl chloride is stirred for 50 minutes at 100 ° C. and then for 40 minutes to 105 ° C./ 28 mbar evacuated.
• 63 g of thionyl chloride-treated potassium fluoride and 1 g of iodine are added under a nitrogen blanket and the mixture is then stirred at 220.degree.
• a mixture of 20 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one and 6.27 g of the potassium fluoride pretreated according to Example 3a is stirred at 300 ° C. for 21 hours. After working up according to Example 9, 15.6 g of an almost colorless distillate of mp 155 to 160 ° C., consisting of 14.85 g (79.3% of theory) of 5-fluoro-2-phenyl-4H -3, l-benzoxazin-4-one and 0.75 g (3.7% of theory) of the starting compound.
• the internal temperature sometimes drops to 315 ° C; the duration of the distillation, which is included in the total reaction time, is set to 1 1/4 hours, the pressure being reduced to 14 mbar towards the end of the reaction. 43.4 g of an almost colorless distillate of mp 147 ° to 158 ° C., consisting of 38.1 g (81.3% of theory) of 5-fluoro-2-phenyl-4H-3,1-benzoxazine- 4-one and 5.2 g (10.4% of theory) of the 5-chloro compound.
• the pulverulent, gray distillation residue (18.3 g) is freed from the inorganic salts by washing with water and dried, 3.2 g of a brown powder remaining as a residue.
• a mixture of 50 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one and 12.4 g of potassium fluoride is passed through a tube heated to 420 to 430 ° C. in an electric tube furnace within 14 minutes then distilled from a connected distillation apparatus at 240 to 244 ° C / 15 mbar. 39.5 g of an almost colorless distillate of mp 144 ° to 156 ° C., consisting of 35.15 g (75% of theory) of 5-fluoro-2-phenyl-4H-3,1-benzoxoxazine -4-one and 4.35 g (8.7% of theory) of the unreacted starting material.
• a mixture of 20 g of 5-chloro-2-phenyl-4H-3,1-benzoxazin-4-one, 6 g of the potassium fluoride pretreated according to Example 3a and 0.3 g of sodium iodide is stirred at 330 ° C. for 3 hours.
• 15.4 g of an almost colorless distillate of mp 162 to 164 ° C. consisting of 15.29 g (81.7% of theory) of 5-fluoro-2-phenyl- 4H-3,1-benzoxazin-4-one and 0.11 g (0.6%) of the unreacted starting material.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)

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• 1984
  • 1984-09-25 DE DE8484111389T patent/DE3476385D1/de not_active Expired
  • 1984-09-25 EP EP84111389A patent/EP0136646B1/fr not_active Expired
  • 1984-09-28 US US06/655,726 patent/US4562254A/en not_active Expired - Lifetime

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